/*
 * Copyright (c) 2001-2008 Caucho Technology, Inc.  All rights reserved.
 *
 * The Apache Software License, Version 1.1
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Burlap", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Scott Ferguson
 */

package com.caucho.hessian.io;

import java.io.IOException;
import java.io.Serializable;
import java.lang.ref.SoftReference;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.WeakHashMap;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Serializing an object for known object types.
 */
public class JavaSerializer extends AbstractSerializer {
	private static final Logger log = Logger.getLogger(JavaSerializer.class.getName());

	private static final WeakHashMap<Class<?>, SoftReference<JavaSerializer>> _serializerMap = new WeakHashMap<Class<?>, SoftReference<JavaSerializer>>();

	private Field[] _fields;
	private FieldSerializer[] _fieldSerializers;

	private Object _writeReplaceFactory;
	private Method _writeReplace;

	public JavaSerializer(Class<?> cl) {
		introspect(cl);

		_writeReplace = getWriteReplace(cl);
	}

	public static Serializer create(Class<?> cl) {
		synchronized (_serializerMap) {
			SoftReference<JavaSerializer> baseRef = _serializerMap.get(cl);

			JavaSerializer base = baseRef != null ? baseRef.get() : null;

			if (base == null) {
				base = new JavaSerializer(cl);
				baseRef = new SoftReference<JavaSerializer>(base);
				_serializerMap.put(cl, baseRef);
			}

			return base;
		}
	}

	protected void introspect(Class<?> cl) {
		if (_writeReplace != null)
			_writeReplace.setAccessible(true);

		ArrayList<Field> primitiveFields = new ArrayList<Field>();
		ArrayList<Field> compoundFields = new ArrayList<Field>();

		for (; cl != null; cl = cl.getSuperclass()) {
			Field[] fields = cl.getDeclaredFields();
			for (int i = 0; i < fields.length; i++) {
				Field field = fields[i];

				if (Modifier.isTransient(field.getModifiers()) || Modifier.isStatic(field.getModifiers()))
					continue;

				// XXX: could parameterize the handler to only deal with public
				field.setAccessible(true);

				if (field.getType().isPrimitive()
						|| (field.getType().getName().startsWith("java.lang.") && !field.getType().equals(Object.class)))
					primitiveFields.add(field);
				else
					compoundFields.add(field);
			}
		}

		ArrayList fields = new ArrayList();
		fields.addAll(primitiveFields);
		fields.addAll(compoundFields);

		_fields = new Field[fields.size()];
		fields.toArray(_fields);

		_fieldSerializers = new FieldSerializer[_fields.length];

		for (int i = 0; i < _fields.length; i++) {
			_fieldSerializers[i] = getFieldSerializer(_fields[i].getType());
		}
	}

	/**
	 * Returns the writeReplace method
	 */
	protected static Method getWriteReplace(Class cl) {
		for (; cl != null; cl = cl.getSuperclass()) {
			Method[] methods = cl.getDeclaredMethods();

			for (int i = 0; i < methods.length; i++) {
				Method method = methods[i];

				if (method.getName().equals("writeReplace") && method.getParameterTypes().length == 0)
					return method;
			}
		}

		return null;
	}

	/**
	 * Returns the writeReplace method
	 */
	protected Method getWriteReplace(Class cl, Class param) {
		for (; cl != null; cl = cl.getSuperclass()) {
			for (Method method : cl.getDeclaredMethods()) {
				if (method.getName().equals("writeReplace") && method.getParameterTypes().length == 1
						&& param.equals(method.getParameterTypes()[0]))
					return method;
			}
		}

		return null;
	}

	public void writeObject(Object obj, AbstractHessianOutput out) throws IOException {
		if (out.addRef(obj)) {
			return;
		}

		Class<?> cl = obj.getClass();

		try {
			if (_writeReplace != null) {
				Object repl;

				if (_writeReplaceFactory != null)
					repl = _writeReplace.invoke(_writeReplaceFactory, obj);
				else
					repl = _writeReplace.invoke(obj);

				// out.removeRef(obj);

				out.writeObject(repl);

				out.replaceRef(repl, obj);

				return;
			}
		} catch (RuntimeException e) {
			throw e;
		} catch (Exception e) {
			// log.log(Level.FINE, e.toString(), e);
			throw new RuntimeException(e);
		}

		int ref = out.writeObjectBegin(cl.getName());

		if (ref < -1) {
			writeObject10(obj, out);
		} else {
			if (ref == -1) {
				writeDefinition20(out);
				out.writeObjectBegin(cl.getName());
			}

			writeInstance(obj, out);
		}
	}

	protected void writeObject10(Object obj, AbstractHessianOutput out) throws IOException {
		for (int i = 0; i < _fields.length; i++) {
			Field field = _fields[i];

			out.writeString(field.getName());

			_fieldSerializers[i].serialize(out, obj, field);
		}

		out.writeMapEnd();
	}

	private void writeDefinition20(AbstractHessianOutput out) throws IOException {
		out.writeClassFieldLength(_fields.length);

		for (int i = 0; i < _fields.length; i++) {
			Field field = _fields[i];

			out.writeString(field.getName());
		}
	}

	public void writeInstance(Object obj, AbstractHessianOutput out) throws IOException {
		try {
			for (int i = 0; i < _fields.length; i++) {
				Field field = _fields[i];

				_fieldSerializers[i].serialize(out, obj, field);
			}
		} catch (RuntimeException e) {
			throw new RuntimeException(e.getMessage() + "\n class: " + obj.getClass().getName() + " (object=" + obj
					+ ")", e);
		} catch (IOException e) {
			throw new IOExceptionWrapper(e.getMessage() + "\n class: " + obj.getClass().getName() + " (object=" + obj
					+ ")", e);
		}
	}

	private static FieldSerializer getFieldSerializer(Class type) {
		if (int.class.equals(type) || byte.class.equals(type) || short.class.equals(type) || int.class.equals(type)) {
			return IntFieldSerializer.SER;
		} else if (long.class.equals(type)) {
			return LongFieldSerializer.SER;
		} else if (double.class.equals(type) || float.class.equals(type)) {
			return DoubleFieldSerializer.SER;
		} else if (boolean.class.equals(type)) {
			return BooleanFieldSerializer.SER;
		} else if (String.class.equals(type)) {
			return StringFieldSerializer.SER;
		} else if (java.util.Date.class.equals(type) || java.sql.Date.class.equals(type)
				|| java.sql.Timestamp.class.equals(type) || java.sql.Time.class.equals(type)) {
			return DateFieldSerializer.SER;
		} else
			return FieldSerializer.SER;
	}

	static class FieldSerializer {
		static final FieldSerializer SER = new FieldSerializer();

		void serialize(AbstractHessianOutput out, Object obj, Field field) throws IOException {
			Object value = null;

			try {
				value = field.get(obj);
			} catch (IllegalAccessException e) {
				log.log(Level.FINE, e.toString(), e);
			}

			try {
				out.writeObject(value);
			} catch (RuntimeException e) {
				throw new RuntimeException(e.getMessage() + "\n field: " + field.getDeclaringClass().getName() + '.'
						+ field.getName(), e);
			} catch (IOException e) {
				throw new IOExceptionWrapper(e.getMessage() + "\n field: " + field.getDeclaringClass().getName() + '.'
						+ field.getName(), e);
			}
		}
	}

	static class BooleanFieldSerializer extends FieldSerializer {
		static final FieldSerializer SER = new BooleanFieldSerializer();

		void serialize(AbstractHessianOutput out, Object obj, Field field) throws IOException {
			boolean value = false;

			try {
				value = field.getBoolean(obj);
			} catch (IllegalAccessException e) {
				log.log(Level.FINE, e.toString(), e);
			}

			out.writeBoolean(value);
		}
	}

	static class IntFieldSerializer extends FieldSerializer {
		static final FieldSerializer SER = new IntFieldSerializer();

		void serialize(AbstractHessianOutput out, Object obj, Field field) throws IOException {
			int value = 0;

			try {
				value = field.getInt(obj);
			} catch (IllegalAccessException e) {
				log.log(Level.FINE, e.toString(), e);
			}

			out.writeInt(value);
		}
	}

	static class LongFieldSerializer extends FieldSerializer {
		static final FieldSerializer SER = new LongFieldSerializer();

		void serialize(AbstractHessianOutput out, Object obj, Field field) throws IOException {
			long value = 0;

			try {
				value = field.getLong(obj);
			} catch (IllegalAccessException e) {
				log.log(Level.FINE, e.toString(), e);
			}

			out.writeLong(value);
		}
	}

	static class DoubleFieldSerializer extends FieldSerializer {
		static final FieldSerializer SER = new DoubleFieldSerializer();

		void serialize(AbstractHessianOutput out, Object obj, Field field) throws IOException {
			double value = 0;

			try {
				value = field.getDouble(obj);
			} catch (IllegalAccessException e) {
				log.log(Level.FINE, e.toString(), e);
			}

			out.writeDouble(value);
		}
	}

	static class StringFieldSerializer extends FieldSerializer {
		static final FieldSerializer SER = new StringFieldSerializer();

		void serialize(AbstractHessianOutput out, Object obj, Field field) throws IOException {
			String value = null;

			try {
				value = (String) field.get(obj);
			} catch (IllegalAccessException e) {
				log.log(Level.FINE, e.toString(), e);
			}

			out.writeString(value);
		}
	}

	static class DateFieldSerializer extends FieldSerializer {
		static final FieldSerializer SER = new DateFieldSerializer();

		void serialize(AbstractHessianOutput out, Object obj, Field field) throws IOException {
			java.util.Date value = null;

			try {
				value = (java.util.Date) field.get(obj);
			} catch (IllegalAccessException e) {
				log.log(Level.FINE, e.toString(), e);
			}

			if (value == null)
				out.writeNull();
			else
				out.writeUTCDate(value.getTime());
		}
	}
}
